Does Fitbit adjust calorie targets?

[E7]

As I've posted before, my calorie target started out way high.  I'm short and kind of small, and Fitbit originally set my calorie target at 2,040 calories per day.  Not once did I actually reach this target, not even on a day when I spent 50 minutes in an intensive rowing class, 20 minutes cycling to that class, and 35 minutes walking to work from the class.  

Yesterday, I noticed that my calorie goal has changed to 1,877.  Did Fitbit learn something and auto-adjust?  Does anyone know what's going on?

I haven't changed my weight, height, or age settings.  The only thing I can think of is that I signed up for the free seven-day trial of Premium, which may have activated something. 

Any ideas?

[Mukluk4]

The premium will set targets based on history.  

[MeowFace]

You can also manually change your calorie goals in your settings on the website or app. Maybe try a calorie calculator online based on your height weight and activity level and use that information to make a educated number for your daily goal.

[Sabstewie]

Is there a way to revert this setting back to auto?